Rotary torso exercises are used to workout the mid-section of the body. Specifically, these exercises target the oblique muscles on both sides of the midsection. Rotating your torso to the right works the right internal and left external oblique muscles. Rotating your torso to the left works the left internal and right external oblique muscles. The rectus abdominis muscle is also involved in both movements. Thus, rotary torso exercises are ideal for overall midsection strengthening. Conditioning the rotary torso muscles is particularly important for sports requiring a swinging motion, such as golf, baseball, tennis, hockey, lacrosse, etc., not only to improve the swing, but to prevent injury. Rotary torso exercise machines are exercise machines, which use resistance or weights, to facilitate these rotary torso exercises.
Commercial use exercise machines for gyms and the like typically target one muscle group and are set up as stations. Users move from station to station to perform a variety of exercises on different muscle groups. Exercise machines that target rotary torso muscles, particularly, traditionally have an arrangement similar to that disclosed in U.S. Pat. No. 4,456,245 to Baldwin issued Jun. 26, 1984. The rotary torso machine is configured so that a user's body is supported in a generally upright seated position, upper and lower torso portions are engaged so as to restrict movement of the user's body to rotary movement of the upper torso relative to the lower torso about an axis extending longitudinally of the user's body, and force (by means of weights in this instance) is imposed to resist such movement.
Many exercise machines, often designed for home use or smaller gyms, are configured to allow the user to perform a variety of exercises, including rotary torso exercises. Because of the multi-use configurations these machines oftentimes are not able to provide the best exercise for any given muscle/muscle group. For example, U.S. Pat. No. 6,015,370 to Pandozy issued on Jan. 18, 2000, discloses an apparatus and a method for performing four exercises including the rotation or torsion of the lower spine and the lower back muscles. As shown in FIG. 8, the user is lying on his back with his upper torso stationary, hips flexed and squeezing one end of a bar between his thighs/knees. The bar is perpendicular to the ground and weights are stacked on a pin at the other end of the bar. At some point between the opposing ends the bar is rotatably mounted on an axle. The exercise is performed by rotation of the hips to the right or left, using stacked free weights as resistance. Another exercise machine advertised on-line by http://www.quantumfitness.com/ab/roto_crunch.shtml, combines a number of mid-torso and abdominal exercises, including a rotary torso machine, on one machine, with the user in the seated position.
Rotary torso exercises with the greatest benefit, are performed with the hips at least partially extended in either a standing or supine position (vice a seated position with hips flexed), so that the targeted oblique and rectus abdominas muscles are able reach maximum extended and flexed positions. In a seated positioned the hips are flexed such that the targeted muscles are necessarily slightly flexed and unable to reach maximum extension during the rotary torso exercises. Performing the exercise in a supine position with hips at least partially extended, vice sitting or standing, also reduces pressure and weight on the lower back and spine, allowing the user to work the targeted area without stress to other areas. Allowing the user to selectively vary the resistance levels as well as the degrees and directions of rotation, further increases the user's ability to effectively target and condition specific muscles in the torso area.
It would be advantageous over the prior art to provide a rotary torso machine, suitable for commercial use, in which a user's body is supported in a generally supine position with hips at least partially extended with the upper and lower torso portions separately supported and engaged so as to restrict movement of the user's body to rotary movement of the upper torso relative to the lower torso about an axis extending longitudinally of the user's body, and free weights are used to impose and to vary resistance to such movement. Additionally it would be advantageous to provide a mechanism that allows the user to engage the resistance at a desired degree of rotation and to vary the degree and direction of rotation. Lastly, it would be advantageous to provide such a rotary torso machine that may be easily converted to an effective back or abdominal exercise machine. Such a machine would be ideal for home or small gym use, where space for multiple exercise machines may be limited.